Dorcas : The Union Flag (not Jack) is indeed the layering of the crosses of
St. George, St. Andrew, and St. Patrick (and there is a right and a wrong way to fly it - naming no names but some streets in London have it wrong at the moment).
Btw, as you mention Scotland don't believe what you hear about a Scotsman never wearing anything under the kilt:
https://ssl4.lon.gb.securedata.net/t...e.php?pID=1783 (hope it works !)